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<head>
    <meta charset="utf-8">
    <title>菜鸟教程(runoob.com)</title>
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<p> arguments.length 属性返回函数接收到参数的个数：</p>
<p id="demo"></p>
<p id="aa"></p>
<script>
    function myFunction(a, b) {
        return arguments.length;
    }

    x = myFunction(3, 4);
    document.getElementById("demo").innerHTML = x;

    const add = (a, b) => {
        alert(a + b)
    }

    add(3, 4);

    const pinfang = a => {
        alert(Math.pow(a, 2))
    }

    pinfang(5)

    const hi = () =>
        "My lover is you!"

    document.getElementById("aa").innerHTML = hi()

    const kiss=(a,b)=>b+"kiss "+a;
    document.getElementById("aa").innerHTML = kiss("ls","徐睿")

    var a,b=12;
    console.log(a)
    console.log(b)
</script>

</body>
</html>